# 728

## 728 is an even composite number composed of three prime numbers multiplied together.

What does the number 728 look like?

This visualization shows the relationship between its 3 prime factors (large circles) and 16 divisors.

728 is an even composite number. It is composed of three distinct prime numbers multiplied together. It has a total of sixteen divisors.

## Prime factorization of 728:

### 23 × 7 × 13

(2 × 2 × 2 × 7 × 13)

See below for interesting mathematical facts about the number 728 from the Numbermatics database.

### Names of 728

• Cardinal: 728 can be written as Seven hundred twenty-eight.

### Scientific notation

• Scientific notation: 7.28 × 102

### Factors of 728

• Number of distinct prime factors ω(n): 3
• Total number of prime factors Ω(n): 5
• Sum of prime factors: 22

### Divisors of 728

• Number of divisors d(n): 16
• Complete list of divisors:
• Sum of all divisors σ(n): 1680
• Sum of proper divisors (its aliquot sum) s(n): 952
• 728 is an abundant number, because the sum of its proper divisors (952) is greater than itself. Its abundance is 224

### Bases of 728

• Binary: 10110110002
• Base-36: K8

### Squares and roots of 728

• 728 squared (7282) is 529984
• 728 cubed (7283) is 385828352
• The square root of 728 is 26.9814751265
• The cube root of 728 is 8.9958828905

### Scales and comparisons

How big is 728?
• 728 seconds is equal to 12 minutes, 8 seconds.
• To count from 1 to 728 would take you about six minutes.

This is a very rough estimate, based on a speaking rate of half a second every third order of magnitude. If you speak quickly, you could probably say any randomly-chosen number between one and a thousand in around half a second. Very big numbers obviously take longer to say, so we add half a second for every extra x1000. (We do not count involuntary pauses, bathroom breaks or the necessity of sleep in our calculation!)

• A cube with a volume of 728 cubic inches would be around 0.7 feet tall.

### Recreational maths with 728

• 728 backwards is 827
• The number of decimal digits it has is: 3
• The sum of 728's digits is 17
• More coming soon!

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"Number 728 - Facts about the integer". Numbermatics.com. 2022. Web. 9 August 2022.

APA style:
Numbermatics. (2022). Number 728 - Facts about the integer. Retrieved 9 August 2022, from https://numbermatics.com/n/728/

Chicago style:
Numbermatics. 2022. "Number 728 - Facts about the integer". https://numbermatics.com/n/728/

The information we have on file for 728 includes mathematical data and numerical statistics calculated using standard algorithms and methods. We are adding more all the time. If there are any features you would like to see, please contact us. Information provided for educational use, intellectual curiosity and fun!

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